THE OBJECTIVES OF THIS STUDY ARE TO: (1) define the dimensions of referral to a regional medical center; (2) define what both parties, the receivers (phsicians at the medical center) and senders (physicians in the local community) feel are optimal components of referral; (3) define congruence and dissonance in comparing ideal and actual practices of both parties in respect to the referral process and then formulate hypotheses as to how these divergent views might affect the "success" or "failure" of referral; (4) implement a prospective study of referred patients to test these hypotheses; (5) involve in all phases of the study the members of the reference center faculty and administration so that they can eventually participate in recommending referral system changes, if necessary. The methodology includes medical record review of a sample of referred hospital and clinic patients to establish a data base describing referrals. Interview schedules will be used with the reference center faculty and with community physicians from several locations which because of their geography relate differently to the reference center. During the prospective study patients will be initially interviewed and then followup will be done by chart review and by telephone.